A second international workshop on natural killer cells is proposed for May 29 through June 1, 1984. The workshop will be a closed meeting of 35 to 50 experts in this area, and will be held at Meadowbrook Hall, a Tudor mansion on the grounds of Oakland University that has been converted into a residential conference facility. The workshop will be divided into five sessions dealing with: purification and biochemical characterization of NK cells, NK target antigens and target recognition sites, the mechanism of NK cytotoxicity, regulation of natural cytotoxicity, and studies of NK clones. These sessions will target the conference to discussions of the mechanism of action of NK cells at the molecular level. Each session will be introduced by one or two experts whose recent work is on the forefront of the session topic, and will proceed with brief presentations and extensive discussions involving all of the participants at the workshop, directed by a chairperson. The organizing committee believes that such a meeting, restricted to natural killer cells, involving a limited number of experts in this area, held in a residential setting and with a workshop format to allow intense discussions will help to resolve some disagreements between laboratories and accelerate the rate of which this phenomenon is characterized at the molecular level. (LB)